英语(英文)版动物世界(动物介绍)introductiontoanimals课件

1、Introduction to AnimalsCharacteristicsMulticellular OrganizationHeterotrophicSexual reproduction and developmentMovementAnimal ClassesAn animal class is made up of animals that are all alike in important ways. Scientists have grouped animals into classes to make it easier to study them.There are man

2、y different animal classes and every animal in the world belongs to one of them. The five most well known classes of vertebrates (animals with backbones) are mammals, birds, fish, reptiles, amphibians. They are all part of the phylum chordata - I remember chordota by thinking of spinal chord.There a

3、re also a lot of animals without backbones. These are called invertebrates and are part of the phylum arthropoda (arthropods). Two of the most commonly known classes in this phylum are arachnids (spiders) and insects.www.kidzone.ws/animals/Mammals People are mammals. So are dogs, cats, horses, duckb

4、ill platypuses, kangaroos, dolphins and whales. What do all these animals have in common, you ask? The answer is MILK! If an animal drinks milk when it is a baby and has hair on its body, it belongs to the mammal classMammals are one of the 6 main classes of animals. Animal classes are groups of ani

5、mals that scientists consider to be alike in some important ways. Mammals are the animal class that people belong to.There are only about 4,000 kinds of mammals. Warm-bloodedBirdsBirds are animals that have feathers and that are born out of hard-shelled eggs.Some people think that what makes an anim

6、al a bird is its wings. Bats have wings. Flies have wings. Bats and flies are not birds. So what makes an animal a bird?The answer is feathers! All birds have feathers and birds are the only animals that do. The feathers on a birds wings and tail overlap. Because they overlap, the feathers catch and

7、 hold the air. This helps the bird to fly, steer itself and land. FishFish are vertebrates that live in water and have gills, scales and fins on their body. There are a lot of different fish and many of them look very odd indeed. There are blind fish, fish with noses like elephants, fish that shoot

8、down passing bugs with a stream of water and even fish that crawl onto land and hop about! ReptilesReptiles are a class of animal with scaly skin. They are cold blooded and are born on land.Snakes, lizards, crocodiles, alligators and turtles all belong to the reptile class. AmphibiansAmphibians are

9、born in the water. When they are born, they breath with gills like a fish. But when they grow up, they develop lungs and can live on land.ArthropodsArthropods is a huge phylum of animals - it includes eleven animal classes: Merostomata, Pycnogonida, Arachnida, Remipedia, Cephalocarida, Branchiopoda,

10、 Maxillopoda, Malacostraca, Chilopoda, Diplopoda, and Insecta. Any animals that have more than four, jointed legs are arthropods. Insects, spiders and crustaceans all belong to this class of animals.ZoologistArachnologistCarcinologistConchologistEntomologistHerptologistIchthyologistMalacologistMamma

11、logistOrnithologistPaleozoologistMarine biologistbotanistMulticellular OrganizationMost animals contain large numbers of cells.Humans contain 50 trillion cells.In most animals, there is a division of labor.Specialization is the adaptation of a cell for a particular function.Tissues are the organizat

12、ion of cells. Cell are able to organize by the joining of cells by cell junctions.Cell specialization has allowed organisms to evolve and adapt to many environments.Animals are HeterotrophicThey must obtain complex organic material from other sources.Most accomplish this through ingestion.Digestion

13、is accomplished within the animal. This process extracts the carbohydrates, protein and lipids from the food eaten.Sexual Reproduction and DevelopmentSexual reproduction restores the diploid number and increases genetic variation.During the developmental process, the zygote undergoes many mitotic di

14、visions. These identical cells must undergo differentiation.Differentiation is process of cell becoming different from each other and being specialized.MovementMost animal are able to move. The ability to move results from the interrelations of two types of tissues found only in animals: nervous tis

15、sue and muscular tissue.There are a few animals that are sessile.Origin and ClassificationThe first animals probably arose from the sea. Taxonomists have grouped animals into several phyla based on evolutionary relationships.Many taxonomist recognize 30 or more animal phyla. We will investigate 11 p

16、hyla. Ten of the phyla include invertebrates and only Chordata includes the vertebrates.Animal Body StructureSymmetryGerm layersBody CavitiesSymmetryAsymmetry refers to the consistent overall pattern of structure of an animal.Animals have three patterns of symmetry.Asymmetry no symmetryRadial Symmet

17、ry similar parts branch in all directions from a central pointBilateral Symmetry- similar halves on either side of a central plane.Patterns of SymmetryIdentify the Type of SymmetryMost animals have a dorsal, ventral, anterior and posterior side or orientation.Dorsal topVentral bottomAnterior headPos

18、terior - tailMost animals exhibit cephalization, the concentration of sensory and brain structures in the anterior. Animals with cephalization have a head!Germ LayersGerm layers are fundamental tissue types found in all animals except sponges (no true tissues).EctodermMesodermEndodermBody CavitiesMo

19、st animals have a fluid filled space that forms between the digestive tract and the outer wall of the body during development. This space is known as a COELOM.Acoelomate (without a coelom) 2 germ layersectoderm and endoderm not separated by a cavity least complex body plan sponges and cnidarians 3 layer acoelomate 3 germ layersendoderm, mesoderm and ectoderm not separated by a cavity flatworms Pseudocoelomate pseudocoelom cavity formed between mesode